diff --git a/service.sh b/service.sh
index c16982f..df361bd 100644
--- a/service.sh
+++ b/service.sh
@@ -1,5 +1,4 @@
 #!/system/bin/sh
-MODDIR=${0%/*}
 
 # Write pending (memory) cached data to disk as a precaution before applying any changes.
 sync
@@ -18,8 +17,8 @@ resetprop -v net.tethering.noprovisioning true
 resetprop -v tether_entitlement_check_state 0
 
 # Don't apply iptables rules until Android has fully booted.
-until [ $(getprop sys.boot_completed) -eq 1 ]; do
-    sleep 1
+until [ "$(getprop sys.boot_completed)" -eq 1 ] && [ -d "/sdcard" ]; do
+    sleep 3
 done
 
 # Bypass TTL/HL detections for only Tether device (server) -> Tethered To devices (client).